Processing system for dispatching tasks and memory access method thereof

ABSTRACT

A processing system includes at least one core, at least one accelerator function unit (AFU), a microcontroller, and a memory access unit. The AFU and the core share a plurality of virtual addresses to access a memory. The microcontroller is coupled between the core and the AFU. The core develops and stores a task in one of the virtual addresses. The microcontroller analyzes the task and dispatches the task to the AFU. The AFU accesses the virtual address indicating where the task is stored through the memory access unit to executes the task.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims priority of China Patent Application No.201910317002.6 filed on Apr. 19, 2019, the entirety of which isincorporated by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The disclosure generally relates to a processing system and its memoryaccess method, and more particularly, it relates to the processingsystem of a heterogeneous processor, an acceleration method, and itsmemory access method.

Description of the Related Art

Hardware accelerators such as an accelerator function unit (AFU) areused mainly to accelerate specific computing tasks. If these computingtasks are performed by the software of a central processing unit (CPU),efficiency will be reduced. The AFU can analyze the computing processand design specialized hardware logic to deal with the computing tasksso that they may be accelerated. The interface between the AFU and CPUcan distribute specific acceleration tasks to the AFU for execution. TheAFU in the prior art is directly connected to the main bus and thesystem memory, which results in two problems: first, the amount of spacein system memory that is available to the AFU is fixed; second, the taskis usually created while the CPU is in the user mode, but it isdistributed to the AFU for execution while in the kernel mode.Therefore, the tasks usually need to be copied from the user space tothe kernel space, which requires a context switch operation and uses uptoo many resources.

In addition, in the current operating system platform of multi-user andmulti-tasks, the AFU are required for several applications or executingstreams. How to allocate several tasks to the AFU for execution becomesa big issue when designing the interface.

In order to satisfy the need to share the AFU between severalapplications or executing streams, several AFUs are often arranged inone chip. However, if there is no coordination and distribution amongthe AFUs, the AFU's task distribution will be unbalanced, and theperformance of the AFUs cannot be fully utilized.

Therefore, a design for a new heterogeneous computing processing systemis needed to overcome the technical problems of dispatching tasks, aswell as of the allocation and distribution of the AFU and CPU asperformed using the current level of technology.

BRIEF SUMMARY OF THE INVENTION

In order to solve the aforementioned problems, the invention proposes aprocessing system and a memory access method that perform scheduling andexecution of memory access requests based on the sequence in whichmemory access requests are received by each accelerator function unit(AFU). In addition, the AFU shares the commonly-used virtual addressspace with the core through the memory access unit of the presentinvention. Therefore, the storage space in system storage can beaccessed dynamically and efficiently to execute the tasks.

In one aspect of the invention, the present invention provides aprocessing system that includes at least one core, at least oneaccelerator function unit (AFU), a microcontroller and a memory accessunit. The AFU shares a plurality of virtual addresses with the core toaccess a memory. The microcontroller is coupled between the core and theAFU. The core develops and stores a task in one of the virtualaddresses, the microcontroller analyzes and dispatches the task to theAFU, and the AFU accesses the virtual address indicating where the taskis stored through the memory access unit to execute the task.

In another aspect of the invention, the present invention provides amemory access method for scheduling, applicable for a processing systemthat includes at least one core, at least one accelerator function unit(AFU), a microcontroller and an memory access unit. The memory accessmethod includes arranging the core and the AFU sharing a plurality ofvirtual addresses to access a memory; developing and storing a task inone of the virtual addresses; analyzing and dispatching the task to theAFU; and accessing the virtual address indicating where the task isstored through the memory access unit to execute the task.

Other aspects and features of the present invention will become apparentto those with ordinarily skill in the art upon review of the followingdescriptions of specific embodiments of the proposed processing systemand memory access method.

BRIEF DESCRIPTION OF DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It shouldbe noted that, in accordance with standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a schematic diagram that illustrates a processing systemaccording to an embodiment of the invention;

FIG. 2 is a schematic diagram that illustrates a processing systemaccording to another embodiment of the invention;

FIG. 3A is a schematic diagram that illustrates a core, an uncore, andthe front end of an accelerator interface according to an embodiment ofthe invention;

FIG. 3B is a schematic diagram that illustrates an uncore, the front endof an accelerator interface, and the back end of an acceleratorinterface according to an embodiment of the invention;

FIG. 4 is a schematic diagram that illustrates a bit map and amicrocontroller map according to an embodiment of the invention;

FIG. 5 is a schematic diagram that illustrates an AFU, amicrocontroller, and a memory access unit according to an embodiment ofthe invention;

FIG. 6 is a schematic diagram that illustrates a scheduler and a memoryre-order buffer according to an embodiment of the invention;

FIG. 7A is a schematic diagram that illustrates pushing the commandpacket into a task queue according to an embodiment of the invention;

FIG. 7B is a schematic diagram that illustrates an AFU sequentiallyexecuting the command packets according to an embodiment of theinvention;

FIG. 8A is a schematic diagram that illustrates executing commandpackets of different task queues according to an embodiment of theinvention;

FIG. 8B is a schematic diagram that illustrates executing commandpackets of different task queues according to another embodiment of theinvention;

FIG. 9 is a schematic diagram that illustrates executing command packetsof different task queues according to another embodiment of theinvention;

FIG. 10 is a schematic diagram that illustrates executing commandpackets of different task queues according to another embodiment of theinvention;

FIG. 11A is a schematic diagram that illustrates a reorder buffer andits related release indicator, return indicator and complete flagaccording to an embodiment of the invention;

FIG. 11B is a schematic diagram that illustrates a reorder buffer andits related release indicator, return indicator and complete flagaccording to another embodiment of the invention;

FIG. 11C is a schematic diagram that illustrates a reorder buffer andits related release indicator, return indicator and complete flagaccording to another embodiment of the invention;

FIG. 11D is a schematic diagram that illustrates a reorder buffer andits related release indicator, return indicator and complete flagaccording to another embodiment of the invention;

FIGS. 12A and 12B are schematics of a heterogeneous processoracceleration method according to an embodiment of the invention;

FIG. 13 is schematic diagram that illustrates a heterogeneous processoracceleration method according to another embodiment of the invention;

FIG. 14 is a memory access method of a processing system for dispatchingtasks according to an embodiment of the invention;

FIG. 15 is a memory access method which utilizes a round-robin methodaccording to an embodiment of the invention;

FIG. 16 is a memory access method which utilizes a round-robin methodaccording to another embodiment of the invention;

FIG. 17 is a memory access method of a processing system for schedulingaccording to an embodiment of the invention;

FIG. 18 is a processor acceleration method for assigning and dispatchingtasks according to an embodiment of the invention;

FIG. 19 is a processor acceleration method for assigning and dispatchingtasks according to another embodiment of the invention;

FIGS. 20A and 20B are processor acceleration methods for assigning anddispatching tasks according to another embodiment of the invention;

FIG. 21 is a processor acceleration method for dispatching tasksaccording to an embodiment of the invention;

FIG. 22 is a processor acceleration method for dispatching tasksaccording to another embodiment of the invention.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF THE INVENTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the subject matterprovided. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

FIG. 1 is a schematic diagram that illustrates a processing system 10according to an embodiment of the invention. The processing system 10includes at least one accelerator function unit (AFU), at least one core120A˜120N, an accelerator interface 130 and a system memory 160. Itshould be noted that there may be any number of cores and AFUs, and thatthey are not required to be identical to each other. As shown in thefigures, the accelerator interface 130 is coupled between several AFU110A˜110N and several cores 120A˜120N. In one embodiment, the processingsystem 10 further includes an uncore 180 which is coupled between theaccelerator interface 130 and several cores 120A˜120N. The processingsystem 10 can be a partial composition of an electronic device. Theabove electronic device can be a mobile electronic device such as a cellphone, a tablet computer, a laptop computer or a PDA, or it can be anelectronic device such as a desktop computer or a server.

In one embodiment, at least one task is established by at least one core120A˜120N. The AFU 110A˜110N is used to execute the above tasks. TheAFUs 110A˜110B are mainly used to accelerate certain computing tasks. Ifthe computing tasks are processed by the core 120A˜120N and itssoftware, efficiency may suffer. The AFUs 110A˜110N are used to analyzecomputing flow and to design specialized hardware logic to deal with thecomputing tasks for acceleration.

For example, the core 120A˜120N and accelerator 110A˜110N can include adigital signal processor (DSP), a microcontroller (MCU), acentral-processing unit (CPU), or a plurality of parallel processorsrelated to the parallel processing environment to implement theoperating system (OS), firmware, driver, and/or other applications ofthe electronic device. It should be noted that, through the acceleratorinterface 130 of the present invention, the core 120A˜120N can assignthe AFU 110A˜110N to perform the acceleration operation by usingspecific commands and without the need for frequent switching betweenthe user mode and the kernel mode.

In one embodiment, corresponding to at least one process operated on thecore 120A˜120N, the core 120A˜120N develops at least one task queue forthe above task in system memory 160. For example, these task queues canbe created by the driver of AFU 110A˜110N according to its correspondingprocess. Each process can create several task queues, and differentprocesses correspond to different task queues. When a lot of datacompression is needed, a process such as compression application cantransfer a specific accelerator command, which is specified by thepresent invention, to inform the accelerator interface 130 to assign acorresponding AFU 110A˜110N to execute the acceleration task.Specifically, the task queue includes a header and at least one commandpacket. The task is implemented using units of command packets. Forexample, a command packet includes type, length, at least one sourceaddress, and at least one target address corresponding to the task. Eachcommand packet is used to describe a task which needs acceleration. Takethe acceleration task of compressing data for example: a certain size ofsource data can be assigned for compression by each command packet. Theheader is used to store information about the process to which the taskqueue belongs.

In addition, the accelerator interface 130 is arranged between the core120A˜120N and the AFU 110A˜110N to receive an accelerator interfaceinstruction about the task which is transmitted from the core 120A˜120N.Afterwards, the accelerator interface 130 indicates the AFU 110A˜110Nbased on the accelerator interface instruction for the AFU 110A˜110N toexecute the above task. The specialized accelerator instruction formatdiffers based on the instruction set of the core 120A˜120N, which can bean X86 instruction or a RISC instruction. The actual function andimplementation of the accelerator instruction will be described in moredetail below. Specifically, the accelerator interface 130 analyzes thetask and dispatches the task to the corresponding AFU 110A˜110Naccording to the features of the task. In one embodiment, theaccelerator interface 130 dispatches the command packet of the taskqueue to one of the AFUs 110A˜110N based on information such as type,length, source address, and target address of the command packet. Itshould be noted that the method of maximizing the overall executionefficiency by dispatching the task to one of the AFUs 110A˜110N isillustrated in more detail below. The description here is focused on thegeneral method used by the processing system 10 that includes one ormany AFUs 110A˜110N.

FIG. 2 is a schematic diagram that illustrates a processing system 10according to another embodiment of the invention. The acceleratorinterface 130 includes an accelerator interface front end 130_FE and anaccelerator interface back end 130_BE to respectively connect the core120 (or the uncore 180 in one embodiment such as FIG. 2) and the AFU110. In one embodiment, the accelerator interface front end 130_FEincludes a decoder 132, the accelerator interface back end 130_BEincludes a microcontroller 140. The processing system 10 furtherincludes a memory access unit 150 coupled between the AFU 110 and themicrocontroller 140 of the accelerator interface 130.

It should be noted that the AFU 110 and the core 120 share a pluralityof virtual addresses to perform the memory access. In one embodiment,the core 120 establishes a task and stores it in one of the virtualaddresses described above. Specifically, the task is created by theprocess operating on the core 120 in user mode based on its ownacceleration requirements. The task is created by putting a commandpacket of the task into a task queue corresponding to the process. Whena task queue corresponding to the process in system memory 160 does notexist, or the corresponding task queue is full, a task queue whichcorresponds to the process should be created at a high priority (thefollowing description is about first establishing a task queue).Specifically, the core 120 transmits an acceleration interfaceinstruction ACCIF_CMD of the task to the microcontroller 140, and themicrocontroller 140 orders the AFU 110 to execute the task (such as acommand packet) based on the acceleration interface instructionACCIF_CMD. In one embodiment, the first sub-command ACCIF_CMD_Creat_QI(also called a first micro-operation, μ op) of the accelerationinterface instruction ACCIF_CMD includes the virtual address in whichthe task is stored, such as the task queue base address, which istransmitted when the core 120 creates a corresponding task queue. Thesecond micro-operation ACCIF_CMD_New_Packet of the accelerationinterface instruction ACCIF_CMD includes the page directory baseaddress, which is transmitted when the core 120 puts the generatedcommand packet into the corresponding task queue.

Afterwards, the decoder 120 of the acceleration interface 130 decodesthe acceleration interface instruction ACCIF_CMD and obtains its owncarried page directory base address to confirm whether the task wascreated successfully or not. The microcontroller 140 analyzes theacceleration interface instruction ACCIF_CMD, obtains the virtualaddress (such as the stored task queue base address) indicating wherethe task (the command packet) is stored, and dispatches the task to thecorresponding AFU 110. It should be noted that in one embodiment, thevirtual address of the task queue of the task is stored within themicrocontroller 140 when the core 120 creates a task queue in systemmemory 160 through the acceleration interface instruction ACCIF_CMD(such as the first micro operation ACCIF_CMD_Creat_QI). Afterwards, whena new task is put into the task queue, the corresponding virtual addresscan be requested directly by the microcontroller 140. The AFU 110accesses the virtual address through the memory access unit 150, andreads the task description (such as the length/target address/sourceaddress of the target data which needs acceleration) of the task toexecute the task.

In one embodiment, after the microcontroller 140 analyzes the task, ittransmits the virtual address to the AFU 110. The AFU 110 reads the datanecessary for executing the task from the system memory 160 based on thevirtual address. In another embodiment, the microcontroller 140 analyzesthe task, obtains the command packet of the task queue of the task basedon the analysis result, and transmits the command packet to the AFU 110so that the AFU 110 can execute the task.

FIG. 3A is a schematic diagram that illustrates a core 120, an uncore180, and the front end of an accelerator interface 130_FE according toan embodiment of the invention. The uncore 180 includes the uncorearbitrator 181 and the uncore scheduler 182 to connect to the core 180and the acceleration interface front end 130_FE respectively.

When several tasks are created by at least one core 120 at the sametime, the uncore arbitrator 181 will dispatch and arbitrate the abovetasks and sequentially deal with the multiple tasks from the core 120 toprevent the processing system 10 from poor efficiency and speed delays.Furthermore, the uncore scheduler 182 determines whether the task shouldbe implemented by the AFU 110 or not based on the features or virtualaddress of the task, in order to determine whether or not the task istransmitted to the acceleration interface front end 130_FE so that theacceleration interface 130 can analyze the task and assign or dispatchthe task.

FIG. 3B is a schematic diagram that illustrates an uncore 180, the frontend of an accelerator interface 130_FE, and the back end of anaccelerator interface 130_BE according to an embodiment of theinvention. The acceleration interface front end 130_FE includes acommand register 131, a decoder 132, a privilege table 134, a register136 and a bit map 137. The acceleration interface back end 130_BEincludes a microcontroller 140 and an active list 147. Themicrocontroller 140 further includes a static random access memory(SRAM) 142 to access the privilege table 134, the bit map 137 and theactive list 147.

In one embodiment, the command register 131 of the accelerationinterface 130 is used to store the acceleration interface instructiontransmitted by the core 120 through the uncore 180. In one embodiment,when the core 120 establishes a new task queue, it transmits a firstmicro operation of the acceleration interface instruction which includesthe virtual address of the task stored in system memory 160. The core120 transmits the virtual address to the acceleration interface frontend 130_FE through the first micro operation. The core 120 stores thevirtual address in an internal microcontroller table of themicrocontroller 140 through the acceleration interface 130. Afterwards,when the core 120 develops a task (such as putting a command packet intothe task queue) in the task queue, it transmits a second micro operationof the acceleration interface instruction to inform the accelerationinterface 130. When the task has set up the privilege successfully(setting up a privilege in a second micro operation is illustrated inmore detail below), the microcontroller 140 analyzes the task and itscorresponding features and content to dispatch the task to one of theAFUs 110A˜110N.

In another embodiment, the second micro operation ACCIF_CMD_New_Packetof the acceleration interface instruction includes a page directory baseaddress to index a page table. Specifically, the page table includesseveral mapping page table entries between each virtual address and eachphysical address of the system memory 160. The above page table includesmultiple levels (two levels will be used as an example, but are notlimited thereto). The page directory base address indicates the storagelocation of the first level page table (also called the page directory).The physical address space of the system memory 160 is divided intounits of pages. For example, each physical page includes 4K bytes, andthe virtual address corresponding to each byte includes 32 bits. Thehigh bits (such as 10 high bits) are used to index the first level pagetable, and each item of the first level page table is directed to thelocation stored in the corresponding second level page table. The middlebits (such as 10 middle bits) are used to index the second level pagetable, and each item in the second level page table is directed to thepage corresponding to the physical address space of the system memory160. The low bits (such as 12 low bits) of each virtual address shift atthe corresponding pages, and the virtual address can be converted into aphysical address by looking up the second level page table. Generallythe process on the core 120 cannot be switched, and its correspondingallocated page directory base address in system memory 160 does notchange. The page directory base address is usually stored in a pagedirectory base address register (PDBR) within the core 120, which isalso called the CR3 control register.

The acceleration interface 130 compares the page directory base addresscarried by the second micro operation ACCIF_CMD_New_Packet with apre-stored page directory base address to confirm whether the task wascreated successfully or not (which is illustrated in more detail in FIG.5). If the page directory base address matches the pre-stored pagedirectory base address, it means that the task was created successfully.If the page directory base address does not match the pre-stored pagedirectory base address, it means that the task was not createdsuccessfully. It should be noted that the above page directory baseaddress is stored by the core 120 in a privilege table 134 of theaccelerator interface 130 in kernel mode. The privilege table 134 storesthe pre-stored page directory base addresses of several processes forcreating tasks when each process needs to dispatch tasks to an AFU 110for execution. In other embodiments, the pre-stored page directory baseaddress can also be stored in a microcontroller table of theacceleration interface 130, or stored in system memory 160 of theprocessing system 10, or stored in the register 136 of the accelerationinterface front end 130_FE, which is not limited by the presentinvention.

When the page directory base address matches the pre-stored pagedirectory base address, the acceleration interface 130 transmits amessage to the core 120 indicating that the task has been createdsuccessfully and updates the bit map 137 about the task. The bit map 137is used to indicate which task queue corresponds to the created task.Afterwards, the microcontroller 140 controls the corresponding AFU 110to read its own corresponding task from the corresponding task queue ofthe system memory 160 based on the updated bit map 137. In theembodiment wherein the AFU 110 includes several AFUs (such as AFUs110A˜110N in FIG. 1), the acceleration interface 130 identifies theprocessing that corresponds to the task based on the page directory baseaddress and allocates it to one of the AFUs 110 based on a certain rule(which is illustrated below). When the acceleration interface 130 readsthe task from the system memory 160, it schedules the AFU 110 to executethe read task.

In another embodiment, when the AFU 110 executes the task, the AFU 110informs the core 120 that the task has been executed by interrupt or amemory-access monitor method. Specifically, when the task has beenexecuted, the command complete flag can be written into a specificaddress in system memory 160 by the AFU 110 or the microcontroller 140,which is the memory-access monitor method of providing this information.In addition, an interrupt notice can also be issued by the AFU 110 orthe microcontroller 140 to immediately inform the core 120 that the taskhas been executed.

Furthermore, in one embodiment, the acceleration interface instructionfurther includes a third micro operation to delete the task queue of thetask. In another embodiment, the acceleration interface instructionfurther includes a fourth micro operation to develop or arrange theregister 136 of the acceleration interface front end 130_FE. Theregister 136 is used to store the privilege table 134, the bit map 137,the acceleration interface instruction or other data and instructions,which is not limited by the present invention.

The function and operating method of the bit map 137 are illustrated inthe following paragraphs. FIG. 4 is a schematic diagram that illustratesa bit map 137 and an active list 147 according to an embodiment of theinvention. When a new task is generated and the page directory baseaddress matches the pre-stored page directory base address tosuccessfully create a task by comparison with the acceleration interface130, the bit map 137 of the new task will be updated. The above bit map137 is used to indicate which task queue corresponding to the newlygenerated task.

As shown in FIG. 4, the active list 147 records several queue numbersTQ1˜TQ4 of the task queues and their corresponding processes PS1˜PS4.For example, the third bit of the bit map 137 is 1, which means that thetask queue of the new task is the task queue with queue number TQ3. Thecontroller 140 can determine, by looking it up in the active list 147,that the task queue with queue number TQ3 corresponds to process PS3.Therefore, the speed of determining the task queue and the processperformed by the acceleration interface 130 can be improved by utilizingthe bit map 137 to manage various kinds of new tasks and allocate themto the proper AFU 110.

The active list 147 can be stored in the SRAM 142 of the microcontroller140 or stored in the register 136. It should be noted that the aboveactive list is for illustration, not for limiting the present invention.For example, the microcontroller 140 can use other methods to record andmanage the task queue and its corresponding process. In addition, theprocess and the task queue can have a one-to-one relationship or aone-to-many relationship. In other words, a process can include one taskqueue or more than two task queues.

FIG. 5 is a schematic diagram that illustrates AFU 110A˜110D, amicrocontroller 140 and a memory access unit 150 according to anembodiment of the invention. The memory access unit 150 includes severalschedulers 210A˜210E and a memory reorder buffer (MOB) 250. Fourschedulers 210A˜210D correspond to four respective AFUs 110A˜110D, andthe scheduler 210E corresponds to the microcontroller 140. The AFUs110A˜110D and/or the microcontroller 140 and at least one core shareseveral virtual addresses of the processing system 10 for accessingmemory (e.g., access the system memory 160) through the memory accessunit 150. In other words, the AFUs 110A˜110D and the microcontroller 140correspond to their own exclusive schedulers 210A˜210E. The number ofschedulers 210A˜210E and AFUs 110A˜110D illustrated above are used forillustration, not for limiting the present invention.

In one embodiment, each AFU 110A˜110D is used to execute at least one ofthe corresponding tasks, and the analyzed tasks correspond to severalmemory access requests. Specifically, a task needs to retrievetask-related data from the system memory 160 through several memoryaccess requests. For example, if a task is compressing 4M of data:Several memory access requests are required to read the data to becompressed in a batch from the system memory 160. After the compressionoperation is accomplished by the AFU 110A˜110D, the compression resultsare written into the system memory 160 in a batch through several memoryaccess requests. Therefore, when the AFU 110A˜110D is assigned toexecute a certain task, a plurality of memory access requests aregenerated by the AFU 110A˜110D based on the task, and the datacorresponding to the memory access request is stored in the virtualaddresses. In addition, when the microcontroller 140 assigns the task toone of the corresponding AFUs 110A˜110D, several memory access requestsneed to be generated so that the task itself can be retrieved from thesystem memory 160 (the virtual address of the task in system memory 160is determined by the task queue base address included in the firstmicro-operation). The schedulers 210A˜210E are coupled to the AFU110A˜110D and the microcontroller 140 to respectively schedule severalmemory access requests which are generated by the AFU 110A˜110D and themicrocontroller 140 and to sequentially transmit the results of thememory access requests to the AFU 110A˜110D and the microcontroller 140.It should be noted that the above task-related data and the task itselfare stored in the above virtual address of the virtual address spacewhich is shared by the core 120, the AFU 110A˜110D and themicrocontroller 140. It should be noted that the physical address spacewhich is mapped by the shared virtual address space belongs to thesystem memory 160. The system memory 160 can also include a multi-levelcache, such as the L1 cache and the L2 cache, which is not limited.

Furthermore, a translation look aside buffer (TLB) is used by the memoryaccess unit 150 to temporarily store several page table entries in apage table which are the most likely to be used by several AFUs110A˜110F during accessing the system memory 160. Each page table entryof the page table is used to store a mapping between a virtual addressand a physical address. Because the AFU 110A˜110D and themicrocontroller 140 share the virtual address space, the data of tasksof different AFUs 110A˜110D and/or microcontroller 140 correspond to thesame virtual address space (such as 4G). However, the physical addressmapped by the identical 4G virtual address space of different AFU110A˜110D and/or microcontroller 140 are different. In order todifferentiate the identical virtual address of the AFU 110A˜110D and themicrocontroller 140, each page table entry stored by the TLB of thepresent invention has a first identification code to indicate the pagetable entry corresponding to one of the AFUs 110A˜110D and/or themicrocontroller 140. Each of the memory access requests has a secondidentification code to indicate the memory access request correspondingto one of the AFUs 110A˜110D and/or the microcontroller 140. The memoryaccess request can evaluate whether or not the second identificationcode matches the first identification code of the page table entry todetermine whether the page table entry belongs to the mappingrelationship of the 4G virtual address space of its own correspondingAFU 110A˜110D and/or microcontroller 140 to determine whether to use thepage table entry or not. In addition, if the memory access unit 150 doesnot successfully execute the corresponding memory access request by thecorresponding page table entry (which is called TLB miss), the memoryaccess unit 150 executes the memory-accessing operation using thecorresponding tablewalk engine of the AFU 110A˜110D and/ormicrocontroller 140 based on the second identification code to load thecorresponding page table entry from the system memory 160 to the TLB.Therefore, in one embodiment of the present invention, theidentification codes are arranged at each page table entry and memoryaccess request in order to identify whether or not the page table entrybelongs to the mapping relationship of its own corresponding virtualaddress space. In addition, a tablewalk operation can be executed whenthe memory access unit 150 does not perform the memory access requestsuccessfully. The tablewalk operation is illustrated in more detail inFIG. 6.

Furthermore, if the memory access unit 150 executes the memory accessrequest successfully and generates a corresponding access result, theschedulers 210A˜210E schedule the above memory access requests based onthe receiving sequence of the memory access requests corresponding tothe tasks from the AFU 110A˜110D and/or microcontroller 140. Afterwards,the memory access unit 150 transmits the results of the memory accessrequests based on the sequence to the corresponding AFU 110A˜110D and/ormicrocontroller 140. Accordingly, even though there are many complicatedtasks, the access result of each task can be transmitted to acorresponding AFU 110A˜110D and/or microcontroller 140 by utilizing thescheduling and dispatching function of the scheduler 210A˜210E.

FIG. 6 is a schematic diagram that illustrates a scheduler 210A˜210E anda memory reorder buffer 250 according to an embodiment of the invention.The MOB 250 includes an arbitrator 281, a pipeline resource 282, a businterface 283 and several tablewalk engines 209A˜209E. Each tablewalkengine 209A˜209E corresponds to one of the schedulers 210A˜210Erespectively.

The pipeline resource 282 includes a first pipeline resource 282A and asecond pipeline resource 282B to execute different memory accessrequests in return. The arbitrator 281 is coupled between the schedulers210A˜210E and the pipeline resource 282 to arbitrate and determine theexecution sequence of the memory access requests. Afterwards, the memoryaccess requests are sequentially transmitted to the first pipelineresource 282A or the second pipeline resource 282B.

Specifically, the arbitrator 281 selects one of the schedulers 210A˜210Eof the AFU 110A˜110D and the microcontroller 140 (the microcontroller140 also has its own corresponding access request, such as a readingtask) using the round-robin method at each clock period, and transmitsone of the memory access requests corresponding to the selectedscheduler to the pipeline resource 282. Accordingly, the AFU selected bythe 281 executes the memory access request to read the data related tothe task through the first pipeline resource 282A or the second pipelineresource 282B. In other words, at each clock period, the arbitrator 281selects the memory access request of one of the schedulers 210A˜210E andtransmits it to the pipeline resource 282 for execution.

In one embodiment, the arbitrator 281 uses the round-robin method, whichmeans inquiring and assigning each scheduler 210A˜210E to sequentiallytransmit a memory access request from the corresponding AFU and/ormicrocontroller 140 to the pipeline resource 282. The first pipelineresource 282A or the second pipeline resource 282B is used to execute amemory access request to read or write task-related data. Therefore,each scheduler 210A˜210E can have an equal opportunity to execute itsown corresponding memory access request.

Afterwards, the pipeline resource 282 receives and executes severalmemory access requests which are transmitted by the schedulers210A˜210E. After the memory access requests have been executed, theexecution results of the memory access requests are transmitted by eachscheduler 210A˜210E to the corresponding AFU 110A˜110D and/ormicrocontroller 140 based on the original sequence of the memory accessrequests. The AFU 110A˜110D can execute the corresponding task based onthe memory access result (such as based on the data to be compressedwhich is read by the memory access request).

As illustrated above, each memory access request has a second respectiveidentification code. In one embodiment, the arbitrator 281 can transmiteach corresponding memory access request to the first pipeline resource282A or the second pipeline resource 282B by determining whether thesecond identification code is odd or even. In other embodiments, thearbitrator 281 can transmit each corresponding memory access request tothe first pipeline resource 282A or the second pipeline resource 282B bydetermining whether the sequence number of the memory access request ateach respective scheduler 210A˜210E is odd or even, which is not limitedby the present invention. When the number of memory access requestsincreases, more than 3 pipeline resources can be arranged to avoiddelays or impacting computing performance.

In another embodiment, the TLB is used by the memory access unit 150 totemporarily store the page table entries which are the most likely to beused by the AFU during accessing memory (e.g., the system memory 160).If the memory access unit 150 does not execute the corresponding memoryaccess request successfully through the corresponding page table entry(TLB miss), the second identification code carried by the memory accessrequest can be used to identify the corresponding tablewalk engine209A˜209E since each one of the tablewalk engines 209A˜209E correspondsto the respective one of AFUs 110A˜110D and microcontroller 140. Thememory access unit 150 can perform the tablewalk operation using thetablewalk engine 209A˜209E that corresponds to the second identificationcode directly based on the second identification code carried by thememory access request. The corresponding tablewalk engine 209A˜209Eloads the corresponding page table entry from the system memory 160 ofthe processing system 10 according to the page directory base addressand the virtual address included in the memory access request through amulti-level table address.

In addition, when the corresponding tablewalk engine 209A˜209E loads acorresponding page table entry from system memory 160, the correspondingtablewalk engine 209A˜209E puts the second identification code of thememory access request at the loaded page table entry as the firstidentification code of the page table entry to represent the one of thescheduler 210A˜210E that corresponds to the page table entry (i.e., thecorresponding one of AFU 110A˜110D and/or microcontroller 140) and torepresent whose mapping relationship the page table entry belongs toamong the AFU 110A˜110D and/or microcontroller 140. It should be notedthat each AFU 110A˜110D and/or microcontroller 140, and itscorresponding one of scheduler 210A˜210E, and its correspondingtablewalk engine has the same page directory base address.

The method of dispatching and allocating several command packets to AFU110 for execution is illustrated in detail below. Now referring to FIG.1, in the embodiment wherein the AFU 110 includes several AFUs110A˜110N, the acceleration interface 130 (or the microcontroller 140 ofFIG. 2) is coupled between the AFU 110 and the core 120 to dispatchseveral command packets to a corresponding AFU 110A˜110N for execution.When any one of the AFUs 110A˜110N executes at least one command packetof several processes, the acceleration interface 130 (or themicrocontroller 140) assigns the AFU 110 to execute other commandpackets of the task queues of the same process at a high priority.

Specifically, the acceleration interface 130 (or microcontroller 140)arranges a time slice for each respective task queue corresponding toeach AFU 110A˜110N, and dispatches the command packets to an AFU whosetime slice of the task queue to which the command packet belongs is notzero using the round-robin method. After the AFU executes the commandpackets, the acceleration interface 130 (or microcontroller 140)decrements the time slice of the AFU of the task queue of the commandpacket.

When the time slice is reduced to 0 or there is no new command packetpushed in the task queue of the executed command packet, themicrocontroller 140 inquires into which process the executed commandpackets belongs to and assigns the AFU 110 to execute the commandpackets of other task queues that correspond to the same process. Inother words, the microcontroller 140 executes the command packets of thetask queue belonging to the same process at a high priority, so as toreduce the number of times of the switching operations switching toother processes, in order to avoid delaying the processing time. Theprocess information of one of the tasks (the command packet) is storedin the header of the task queue where the task stores.

It should be noted that each AFU 110A˜110N arranges a time slice foreach respective task queue. The time slice of each task queue isindependent of the others. Therefore, an AFU 110 can simultaneously haveseveral time slices for different task queues. By arranging time slicesfor several task queues and executing the round-robin method, thecommand packets of several task queues can be equally distributed anddispatched to avoid over-distributing and executing a certain portion oftask queues and ignoring another portion of the task queues. It shouldbe noted that the arrangement of the round-robin method and the timeslices for several task queues is applicable to a processing system 10with several AFUs 110A˜110D, but will not be limited. It can also beapplied in a processing system 10 that includes only one AFU 110 fordispatching the command packets of several task queues (or processes).

In another embodiment, when several command packets executed by any oneof the AFUs 110A˜110D have relevance, the microcontroller 140 assignsthe AFU to execute other command packets having the relevance at a highpriority. For example, when several continuous command packets are usedto compress data of the same file, the above command packets have therelevance. Specifically, when a command packet and its previous commandpackets correspond to the same context information, the above commandpackets have the relevance. Afterwards, the context information is usedby the AFU 110 to execute the relevant command packet. The contextinformation can be stored temporarily in the internal RAM 116 of the AFU110.

In addition, when the command packets do not have relevance, themicrocontroller 140 accesses the system memory 160 of the processingsystem 10 to execute the context-save operation or the context-restoreoperation. In other words, the microcontroller 140 obtains and storesthe corresponding context information in system memory 160 or in theinternal RAM 116. Furthermore, the above command packet further includesa dependent start indication and a dependent end indication to representthe beginning and end of the relevance.

Therefore, the microcontroller 140 can determine whether the relevanceof the command packets finishes based on the dependent start indicationand the dependent end indication. In one embodiment, when the time sliceis reduced to 0 but the relevance of the command packets is not at anend, the microcontroller 140 increments N for the time slice, wherein Nis a positive integer greater than 1. In other words, themicrocontroller 140 keeps dispatching the relevant command packets untilthe relevance ends.

The method of dispatching multiple command packets to the AFU forexecuting the command packets is illustrated with detailed embodimentsbelow. FIG. 7A is a schematic diagram that illustrates pushing thecommand packets P11˜P31 into task queues TQ1˜TQ3 according to anembodiment of the invention; FIG. 7B is a schematic diagram thatillustrates two AFUs 110A and 110B sequentially executing the commandpackets P11˜P31 according to an embodiment of the invention.

As shown in FIG. 7A, the task queue TQ1 includes 4 command packetsP10˜P13, the task queue TQ2 includes 4 command packets P20˜P23, and thetask queue TQ3 includes 2 command packets P30˜P31. In addition, the 3task queues TQ1˜TQ3 belong to different processes, and the initial valueof the time slice is 3. First, the microcontroller 140 respectivelydispatches the command packets P10˜P13, P20˜P23 of the task queues TQ1and TQ2 to the AFU 110A and 110B. Whenever the AFU 110A and 110Bexecutes a command packet, the value of the time slice of the taskqueues TQ1 and TQ2 will be decremented.

Because the initial value of the time slice is 3, when the AFU 110Aexecutes 3 command packets P10˜P12, the value of the time slice of thecorresponding task queue TQ1 is zero. Therefore, the microcontroller 140will distribute the command packet of other task queues to the AFU 110Awhich belong to the same process of the task queue TQ1. Similarly, whenthe AFU 110B executes 3 command packets P20˜P22, the value of the timeslice of the corresponding task queue TQ2 is 0. Therefore, themicrocontroller 140 will distribute the command packet of other taskqueues to the AFU 110A which belong to the same process of the taskqueue TQ2.

Regarding the AFU 110A, the process of task queues TQ2 and TQ3 isdifferent from the process of task queue TQ1. Therefore, themicrocontroller 140 can assign the command packets of task queue TQ2 orTQ3 to the AFU 110A. However, because the time slice of task queue TQ2corresponding to AFU 110B has been reduced to 0, the microcontroller 140dispatches the command packet of task queue TQ3 to the AFU 110A based onthe round-robin method, and it does not dispatch the command packet oftask queue TQ2 to the AFU 110A.

Similarly, regarding the AFU 110A, because the time slice of task queueTQ1 corresponding to AFU 110A has been reduced to 0, the microcontroller140 dispatches the command packet of task queue TQ3 to the AFU 110Bbased on the round-robin method, and it does not dispatch the commandpacket of task queue TQ1 to the AFU 110B. Therefore, as shown in FIG.7B, the AFU 110A executes the 4 command packets P10˜P12 and P30sequentially, and the AFU 110B executes the 4 command packets P20˜P22and P31 sequentially.

FIG. 8A is a schematic diagram that illustrates executing commandpackets of different task queues TQ1˜TQ3 according to an embodiment ofthe invention. In the embodiment, the two task queues TQ1 and TQ2 belongto process A, and task queue TQ3 belongs to process B, which isdifferent from process A. As shown in the figure, the microcontroller140 dispatches the command packets P10 and P11 of the task queue TQ1 insequence, and the time slice corresponding to the task queue TQ1 hasbeen reduced to 0. Therefore, the microcontroller 140 distributes thecommand packets P20˜P22 of another task queue TQ2 of the same process A.

Afterwards, the time slice corresponding to the task queue TQ2 has beenreduced to 0. Because process B of task queue TQ3 is different fromprocess A, the microcontroller 140 will distribute the command packetP12 of task queue TQ1 of process A. Specifically, the time slicecorresponding to the task queue TQ1 has been reduced to 0, themicrocontroller 140 increments the time slice of the task queue TQ1 by 1(which refers to the number of command packets which have not beendispatched) to assign the command packet P12 of the task queue TQ1 ofthe process A. In addition, in another embodiment, if the relevance ofthe command packets P10˜P12 does not end, the microcontroller 140 canalso increments the time slice of the task queue TQ1 by 1 (which refersto the number of command packets that are relevant) to assign thecommand packet P12 of task queue TQ1 of process A.

FIG. 8B is a schematic diagram that illustrates executing commandpackets of different task queues TQ1˜TQ3 according to another embodimentof the invention. The embodiment is similar to the embodiment of FIG.8A, but the 3 task queues belong to process A. Therefore, after themicrocontroller 140 dispatches the command packets P20˜P22 of task queueTQ2 of process A, it can dispatch the command packet P30 of another taskqueue TQ3 of process A to prevent task queue TQ3 from waiting for a longtime.

FIG. 9 is a schematic diagram that illustrates executing command packetsof different task queues TQ1˜TQ3 according to another embodiment of theinvention. In the embodiment, process A includes task queue TQ2, anotherprocess B includes task queues TQ1 and TQ3, the command packets P10˜P12of task queue TQ1 are relevant, and the command packets P20˜P22 of taskqueue TQ2 are not relevant. Because process A, which corresponds to taskqueue TQ2, is different from process B, which corresponds to task queuesTQ1 and TQ3, if the time slice of task queue TQ2 has not been reduced to0, the microcontroller 140 will dispatch all command packets of the taskqueue TQ2 and then assign the task queue of other processes.

After the microcontroller 140 assigns the command packets P20˜P22 of thetask queue TQ2, it will assign the command packets P10˜P12 of the taskqueue TQ1 of another process B. It should be noted that because thecommand packets P10˜P12 of the task queue TQ1 are relevant, when therelevant command packets P10˜P12 have been distributed, themicrocontroller 140 will distribute the irrelevant command packetsP30˜P32 of another task queue TQ3 of the same process A.

FIG. 10 is a schematic diagram that illustrates executing commandpackets of different task queues TQ1˜TQ3 according to another embodimentof the invention. The embodiment is similar to the embodiment of FIG. 9,but the command packets P10˜P12 of the task queue TQ1 are not relevant.Therefore, after the microcontroller 140 dispatches the command packetP10 of the task queue TQ1, it can dispatch other irrelevant commandpackets which belong to the same process. Therefore, the microcontroller140 dispatches the command packet P30 of the task queue TQ3 of theprocess B based on the round-robin method, and it does not dispatch thecommand packet P11 of the task queue TQ1. Afterwards, themicrocontroller 140 further dispatches the command packet P11 of thetask queue TQ1 of the process B based on the round-robin method.

The method of dispatching and distributing command packets through thereorder buffer with the bit map 137 and the active list 147 isillustrated below. In one embodiment, the acceleration front end 130_FEreceives and decodes the acceleration interface instruction to set upthe bit map 137. Specifically, the acceleration interface instruction isthe second micro operation ACCIF_CMD_New_Packet, which is generated bythe core 120 when it generates and pushes the new command packet intothe corresponding task queue.

Afterwards, the acceleration back end 130_BE updates the active list 147based on the bit map 137, selects one of the command packets from one ofthe task queues based on the active list 147, and dispatches theselected command packet to the corresponding AFU 110. It should be notedthat the bit map 137 is used to indicate the task queue which containsthe newly generated command packets. The active list 147 is used toindicate which task queue has the command packets, which means that thetask queue is not empty. In addition, as shown in the active list ofFIG. 4, the active list 147 can be used to indicate which processcorresponds to the task queue having the above command packets. In otherwords, the task queue of the process is not empty, and it has at leastone command packet.

After the above selected command packets are dispatched to thecorresponding AFU 110, they will not be executed immediately. Even ifthey are executed immediately, the time it takes for the AFU 110 toexecute each command packet is different. Therefore, command packetswhich are dispatched earlier might be accomplished later. In anotherembodiment, a reorder buffer (ROB) can be arranged so that each taskqueue (not shown) can schedule the command packets in the originalsequence of the command packets in each task queue. Afterwards, theacceleration interface 130 returns the command packets—those which havebeen executed by the AFU 110—to the core 120 based on the originalsequence. Because the time it takes the AFU 110 to execute each commandpacket is different, the execution results of each command packet can bereturned to the core 120 based on the original sequence by utilizing theROB to avoid mistakes due to an inconsistent sequence. In addition, theROB can be stored in the SRAM 142 of the acceleration interface 130.

Accordingly, when the acceleration interface 130 dispatches severalcommand packets to several AFUs 110 for simultaneous execution, theacceleration interface 130 returns the executed command packetssimultaneously to the core 120 according to the original sequence of thepackets in the task queue. Specifically, the ROB further includes arelease indicator and a return indicator. The release indicator is usedto indicate the next command packet to be dispatched to the AFU 110, andthe return indicator is used to indicate the next command packet to bereturned to the core 120. Furthermore, the ROB stores a complete flagcorresponding to each command packet to indicate whether the executionof each corresponding command packet has been completed or not.

FIGS. 11A˜11D are schematics of a reorder buffer and its related releaseindicator PIN, return indicator PRT, and complete flags C00˜C05,according to an embodiment of the invention. In the embodiment, severalentries of the ROB have several complete flags C00˜C05 to indicatewhether the execution of the corresponding command packets have beencompleted or not. The bit 0 means that the execution of thecorresponding command packet has not been completed, and the bit 1 meansthat the execution of the corresponding command packet has beencompleted.

Firstly in FIG. 11A, all command packets P00˜P05 have not beendispatched and executed, and therefore their corresponding completeflags C00˜C05 are all 0. The release indicator PIN and the returnindicator PRT point to the first entry of the ROB, which is the entrycorresponding to the command packet P00.

Afterwards, in FIG. 11B, the microcontroller 140 distributes the commandpackets P00˜P03 to the AFU 110, but the AFU 110 has not finished theexecution. Therefore, the complete flags C00˜C03 are 0, but the releaseindicator PIN points to the corresponding entry of the command packetP04 to indicate that the next one to be dispatched to the AFU 110 forexecution is the command packet P04.

Afterwards, in FIG. 11C, the execution of the command packets P01 andP02 have been completed, and their corresponding complete flags C01 andC02 are 1 while other complete flags are still 0. It should be notedthat because the complete flag C00 of the first entry of the ROB (thecorresponding entry of the command packet P00) is 0, therefore, themicrocontroller 140 cannot return the executed command packets P01 andP02 to the core 120 based on the original sequence.

Afterwards, in FIG. 11D, the execution of the command packet P00 hasbeen completed, and its corresponding complete flag C00 is 1accordingly. Because the first complete flag C00 of the ROB is 1,therefore, the microcontroller 140 returns the executed command packetsP01 and P02 to the core 120 based on the original sequence. Furthermore,the return indicator PRT points to the corresponding entry of thecommand packet P03 to indicate that the next one to be returned to thecore 120 is the command packet P03.

The various acceleration, scheduling and access methods of variousprocessing systems and heterogeneous processors of the present inventionare illustrated in detail below. FIGS. 12A and 12B are schematics of aheterogeneous processor acceleration method according to an embodimentof the invention, which is mainly executed by the core 120. In stepS1201, the core 120 initiates the AFU 110. Specifically, the core 120determines whether the processing system 10 includes an available AFU110 or not. If yes, the AFU 110 will be initiated; if not, theheterogeneous processor acceleration method ends. In step S1202, thecore 120 pre-stores the pre-stored page directory base address of thetask to the privilege table 134 in kernel mode. In step S1203, the core120 develops a task queue corresponding to the task on the system memory160 in user mode.

Afterwards, in step S1204, the core 120 prepares and transmits the firstmicro operation of the acceleration interface instruction of the task tothe acceleration interface 130 through the uncore 180. The aboveacceleration interface instruction includes the virtual address of thetask queue.

In step S1208, the uncore 180 determines whether the task should beexecuted by the AFU 110 or not by the virtual address. If it isdetermined that the task should not be executed by the AFU 110, stepS1204 will be executed again. If it is determined that the task shouldbe executed by the AFU 110, step S1210 will be executed to store thevirtual address in the microcontroller table through the accelerationinterface 130. In step S1211, when at least one task (such as pushing atleast one command packet) is developed during the task queue in usermode, a second micro operation of the acceleration interface instructionof the task is transmitted to the acceleration interface 130 through theuncore 180. The above second micro operation includes a page directorybase address.

In step S1212, the page directory base address and the pre-stored pagedirectory base address are compared by the acceleration interface 130 toconfirm whether the task has set up a privilege successfully, whereinthe second micro operation includes the above mentioned page directorybase address. If the task has not set up the privilege successfully,step S1204 will be executed again; if the task has set up the privilegesuccessfully, step S1214 will be executed so that the core 120 receivesthe message from the acceleration interface 130 indicating that the taskhas set up the privilege successfully. Afterwards, in step S1216, thecore 120 executes tasks other than this task. In step S1218, the core120 receives a message indicating that the task from the AFU 110 hasbeen accomplished.

FIG. 13 is schematic diagram that illustrates a heterogeneous processoracceleration method according to another embodiment of the invention,which is mainly executed by the acceleration interface 130. In stepS1302, an acceleration interface 130 is arranged between the core 120and the AFU 110. In step S1304, an acceleration interface instruction,which includes a page directory base address to index a page table, isreceived for the AFU 110 to execute a task. In step S1306, theacceleration interface instruction is decoded through the accelerationinterface 130 to generate a corresponding micro operation.

Afterwards, in step S1310, the page directory base address is comparedwith a pre-stored page directory base address to confirm whether thetask has set up the privilege successfully. If the task has not set upthe privilege successfully, step S1304 will be executed again; if thetask has set up the privilege successfully, step S1312 will be executedso that a message will be transmitted to the core 120 indicating thatthe task has set up the privilege successfully. Afterwards, in stepS1314, the bit map 137 of the task is updated, the corresponding taskqueue is read, and a corresponding AFU 110 is arranged to execute thetask based on the task queue in the system memory 160.

FIG. 14 is a memory access method of a processing system for dispatchingtasks according to an embodiment of the invention. In step S1402,several AFUs 110 and a core 120 are arranged to share several virtualaddresses to access a memory (i.e., the system memory 160). In stepS1404, the core 120 develops and stores a task in one virtual address.As shown in FIG. 12A, developing a task means pushing a command packetinto a task queue with a virtual address as the queue base address. Instep S1406, the microcontroller 140 analyzes and dispatches the task toone of the AFUs 110 based on the features of the task. Afterwards instep S1408, the AFU 110 accesses the virtual address indicating wherethe task is stored through the memory access unit 150. In step S1410,the AFU 110 executes the task.

It should be noted that if the AFU 110 and core 120 do not share severalvirtual addresses for accessing memory, after the AFU 110 accomplishesthe task, it should write the data to the hard disk or system memory160. Afterwards, the core 120 reads the data, and it takes twodata-moving processes from the hard disk to the system memory 160. Onthe contrary, AFU 110 and core 120 are arranged by the present inventionto share several virtual addresses for accessing memory to simplify andaccelerate the data moving process.

FIG. 15 is a memory access method which utilizes a round-robin methodaccording to an embodiment of the invention. In step S1502, the tasksare dispatched to one of several AFUs 110 based on the features of thetasks. In step S1504, the arranged AFU 110 generates several memoryaccess requests based on the corresponding tasks. In step S1506, one ofthe AFUs 110 is arranged based on the round-robin method at each clockperiod for transmitting one of the memory access requests of thecorresponding task to the pipeline resource 282.

Afterwards, in step S1508, the assigned AFU 110 executes the memoryaccess request through the pipeline resource 282 to read thetask-related data from the system memory 160. In step S1510, theexecuting result of the memory access request is transmitted to the AFU110 which is assigned by the arbitrator 281. The arrangement of theabove arbitrator 281 and the pipeline resource 282 is shown in FIG. 6,and will not repeated again here.

FIG. 16 illustrates a memory access method which utilizes a round-robinmethod according to another embodiment of the invention. In step S1602,several AFUs 110 and cores 120 are arranged to share several virtualaddresses to access a memory (i.e., the system memory 160), and anidentification code is arranged for each memory access request of thetask to indicate the AFU 110 and/or microcontroller 140 of thecorresponding page table entry. In other words, each memory accessrequest has its own exclusive identification code to rapidly inquireinto the corresponding memory access request subject (the AFU 110 and/ormicrocontroller 140).

In step S1606, a translation look aside buffer (TLB) is used by thememory access unit 150 to temporarily store several page table entriesin a page table which are the most likely to be used by several AFUs110A˜110F during accessing the memory. Specifically, each page tableentry stores a mapping between a virtual address and a physical address.In step S1608, when the memory access request is not successfullyaccessing the memory by the temporarily-stored page table entry, thepipeline resource 282 transmits the memory access request to thecorresponding tablewalk engines 209A˜209E based on the identificationcode in order to load corresponding page table entry from the systemmemory 160. In other words, as shown in FIG. 5 and FIG. 6, the AFU110A˜110D and microcontroller 140 have their own exclusive andcorresponding schedulers 210A˜210E and tablewalk engines 209A˜209E.

Afterwards, in step S1609, the corresponding one of the tablewalkengines 209A˜209E searches a multi-level page table to load acorresponding page table entry to the TLB based on the virtual addressincluded in the memory access request and a page directory base address.In step S1610, when the corresponding one of the tablewalk engines209A˜209E loads a corresponding page table entry from system memory 160,the identification code of the memory access request is written to theloaded page table entry. In step S1611, each corresponding memory accessrequest is transmitted to the first pipeline resource 282A or the secondpipeline resource 282B by determining whether the identification code isodd or even. Therefore, by the distributing arrangement of the firstpipeline resource 282A and the second pipeline resource 282B associatedwith the above identification code, the processing speed of the memoryaccess request can be accelerated. In addition, because the page tableentry from the system memory 160 has been filled with the identificationcode, the identification code can determine whether or not the filledpage table entry corresponds to the memory access request.

FIG. 17 is a memory access method of a processing system for schedulingaccording to an embodiment of the invention. In step S1702, severalschedulers 210A˜210E are arranged. Each scheduler corresponds torespective one of the AFUs 110 and microcontroller 140. In step S1704,the memory access requests are scheduled based on the sequence in whichthe memory access requests were received by the corresponding AFU 110 ormicrocontroller 140. In step S1706, each scheduler 210A˜210E is assignedusing the round-robin method for transmitting the memory access requestsof the corresponding AFU 110 or microcontroller 140 to the pipelineresource 282. In step S1708, the pipeline resource 282 receives andexecutes the memory access requests transmitted from the schedulers210A˜210E. In step S1710, each scheduler 210A˜210E transmits the memoryaccess results of the memory access requests to the corresponding AFU110 or the microcontroller 140 based on the sequence of step S1704.

FIG. 18 is a processor acceleration method for assigning and dispatchingtasks according to an embodiment of the invention. In step S1801, amicrocontroller 140 is arranged between at least one AFU 110 and thecore 120. In step S1802, at least one task queue is developed for one ofthe operating processes through the core 120.

Afterwards, in step S1803, the core 120 generates and pushes the commandpackets into the corresponding task queue. In step S1804, themicrocontroller 140 dispatches the command packets to the correspondingAFU 110 for execution. In step S1806, when the command packet executedby any of the AFUs 110 belongs to one of the processes, themicrocontroller 140 assigns the AFU 110 to execute other command packetsof the task queue of the process at a high priority. It should be notedthat the processing method of FIG. 18 does not limit the number of AFUs110. The processor acceleration method of the invention may be appliedto a processing system 10 that includes one or several AFUs 110 forassigning and dispatching tasks.

FIG. 19 is a processor acceleration method for assigning and dispatchingtasks according to another embodiment of the invention. In step S1902, atime slice is arranged for each respective task queue corresponding toeach AFU 110. In step S1904, each of the command packets is dispatchedto the AFU with a non-zero time slice for the task queue to which thecommand packet belongs using the round-robin method. In step S1906,after the command packet is executed, the value of the correspondingAFU's time slice corresponding to the task queue to which the commandpacket belongs is decremented by 1.

In step S1908, a determination is made as to whether or not the timeslice is reduced to 0, or whether there is no new command packet putinto the task queue to which the executed command packet belongs. Whenthe time slice is not reduced to 0 or there is new command packets inthe task queue to which the executed command packet belongs, step S1906is executed again. When the time slice is reduced to 0 or there is nonew command packet that has been put into the task queue to which theexecuted command packet belongs, step S1910 is executed. In step S1910,the microcontroller 140 inquires which process the executed commandpackets belongs to. In step S1912, the microcontroller 140 assigns theAFU to execute the command packet of the other task queue correspondingto the same process. It should be noted that the processing methodillustrated in FIG. 19 does not limit the number of AFUs 110. Aprocessing system 10 that includes one or several AFUs 110 can use theprocessor acceleration method of the invention for assigning anddispatching tasks.

FIGS. 20A and 20B are processor acceleration methods for assigning anddispatching tasks according to another embodiment of the invention. Instep S2002, the core 120 runs several processes and develops at leastone task queue corresponding to each process, and generates and pushesseveral command packets into the corresponding task queues. In stepS2004, the microcontroller 140 dispatches several command packets to thecorresponding AFU 110 for execution.

Afterwards, in step S2006, whether or not the AFU 110 executes thecommand packets of one of the processes is determined. If the AFU 110does not execute the command packets of the process, step S2004 will beexecuted again. If the AFU 110 executes the command packets of theprocess, step S2008 will be executed so that the microcontroller 140dispatches the AFU 110 to execute other command packets of the taskqueues which belong to the same process at a high priority.

In step S2010, whether the command packets executed by the AFU 110 arerelevant or not is determined. If the command packets executed by theAFU 110 are relevant, step S2012 will be executed so that themicrocontroller 140 distributes the AFU 110 to execute other relevantcommand packets at a high priority. If the command packets executed bythe AFU 110 are not relevant, step S2018 will be executed so that themicrocontroller 140 accesses the system memory 160 to execute thecontext-save operation or the context-restore operation.

Afterwards, in step S2014, whether or not one of the command packets andits previous command packets correspond to the same context informationis determined. If the command packets do not have the same contextinformation as the previous command packets, step S2012 will beexecuted. If the command packets have the same context information asthe previous command packets, step S2016 will be executed so that theAFU 110 uses the context information to execute the command packetshaving the same context information. The context information can betemporarily stored in the internal RAM 116 of the AFU 110. It should benoted that the processing method of FIG. 20 does not limit the number ofAFUs 110. A processing system 10 with one or several AFUs 110 can usethe processor acceleration method of the invention for assigning anddispatching tasks.

FIG. 21 is a processor acceleration method for dispatching tasksaccording to an embodiment of the invention. In step S2100, at least onecore runs several processes and develops at least one task queue foreach corresponding process. In step S2101, the core 120 generates andpushes several command packets into the corresponding task queue, andtransmits an acceleration interface instruction about the task queue. Instep S2102, an acceleration interface 130 is arranged between the AFU110 and the core 120 to receive the acceleration interface instruction.

Afterwards, in step S2104, a bit map 137 is arranged based on theacceleration interface instruction to indicate the task queues whichcontain the generated command packets. In step S2108, the accelerationinterface 130 updates an active list 147 based on the bit map 137, andselects one of the command packets from one of the task queues based onthe active list 147. Afterwards, in step S2110, the accelerationinterface 130 distributes the selected command packet to the AFU 110 forexecution based on the relevance of the command packets.

FIG. 22 is a processor acceleration method for dispatching tasksaccording to another embodiment of the invention. In step S2202, a ROBis arranged for each task queue to schedule several command packetsbased on the original sequence of the command packets in each taskqueue. In step S2204, a release indicator is arranged at the ROB toindicate the next command packet at the ROB to be dispatched to the AFU110. In step S2206, a return indicator is arranged at the ROB toindicate the next command packet at the ROB to be returned to the core120.

In step S2208, the AFU 110 executes the above command packets. In stepS2210, a complete flag is arranged for each command packet at the ROB todetermine whether the execution of the command packet has beencompleted. If the execution of the command packet has not beencompleted, step S2208 will be executed so that the AFU 110 executes theabove command packets. If the execution of the command packet has beencompleted, step S2211 will be executed to return the completed commandpackets to the core 120 based on the original sequence of the commandpackets. Afterward, in step S2212, the return indicator is amended toindicate the command packet which is next to all of the completed andreturned command packets.

Use of ordinal terms such as “first”, “second”, “third”, etc., in theclaims to modify a claim element does not by itself connote anypriority, precedence, or order of one claim element over another or thetemporal order in which acts of a method are performed, but are usedmerely as labels to distinguish one claim element having a certain namefrom another element having the same name (but for use of the ordinalterm) to distinguish the claim elements. The term “access” of thespecification and the claims is the abbreviation of term “memoryaccess”, which includes loading data from the system storage and/orstoring data to the system storage. In addition, the “system storage”can also be “memory” in other embodiments.

While the invention has been described by way of example and in terms ofthe preferred embodiments, it should be understood that the invention isnot limited to the disclosed embodiments. On the contrary, it isintended to cover various modifications and similar arrangements (aswould be apparent to those skilled in the art). Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements.

What is claimed is:
 1. A processing system, comprising: at least onecore; at least one accelerator function unit (AFU); a microcontroller,coupled between the core and the AFU; and a memory access unit, whereinthe core develops and stores a task in one of a plurality of virtualaddresses, the microcontroller analyzes and dispatches the task to theAFU, and the AFU accesses the virtual address indicating where the taskis stored through the memory access unit to execute the task; whereinthe core, the AFU and the microcontroller share the plurality of virtualaddresses; wherein the core transmits an acceleration interfaceinstruction about the task to the microcontroller, and the accelerationinterface instruction comprises a page directory base address of thetask; wherein the microcontroller compares the page directory baseaddress and a pre-stored page directory base address to respond to thecore whether or not the task has set up a privilege successfully.
 2. Theprocessing system in claim 1, wherein the core transmits an accelerationinterface instruction about the task to the microcontroller, and theacceleration interface instruction comprises the virtual address inwhich the task is stored.
 3. The processing system in claim 1, whereinthe page directory base address is used to index a page table, whereinthe page table comprises a plurality of page table entries for storing amapping between each of the virtual addresses and a physical address. 4.The processing system in claim 3, wherein the memory access unit uses atranslation look aside buffer (TLB) to temporarily store the page tableentries which are most likely to be used by the AFU during accessing thememory.
 5. The processing system in claim 4, wherein the memory accessunit further comprises: a tablewalk engine, wherein when the AFU failsto access the memory through the TLB, the tablewalk engine is used toload a corresponding page table entry from a system memory of theprocessing system based on the page directory base address.
 6. Theprocessing system in claim 1, wherein the AFU generates a plurality ofmemory access requests based on the task, and the data corresponding tothe memory access requests is stored in the virtual addresses.
 7. Theprocessing system in claim 6, wherein the memory access unit furthercomprises: a scheduler, coupled to the AFU, used to schedule the memoryaccess requests corresponding to the tasks, and transmits results of thememory access requests to the AFU.
 8. The processing system in claim 7,wherein the memory access unit further comprises: a pipeline resource,receiving the memory access requests transmitted by the scheduler sothat the AFU executes the memory access requests for access the memorythrough the pipeline resource.
 9. A memory access method, applicable forat least one core, at least one accelerator function unit (AFU), amicrocontroller, and a memory access unit, the memory access methodcomprising: developing and storing a task in one of a plurality ofvirtual addresses; analyzing and dispatching the task to the AFU;accessing the virtual address indicating where the task is storedthrough the memory access unit to execute the task; transmitting anacceleration interface instruction about the task to themicrocontroller, wherein the acceleration interface instructioncomprises the page directory base address of the task; and comparing thepage directory base address and a pre-stored page directory base addressto respond to the core whether the task has set up a privilegesuccessfully or not by the core; wherein the core, the AFU and themicrocontroller share the plurality of virtual addresses.
 10. The memoryaccess method in claim 9, further comprising: transmitting anacceleration interface instruction about the task to themicrocontroller, wherein the acceleration interface instructioncomprises the virtual address containing the task.
 11. The memory accessmethod in claim 9, wherein the page directory base address is used toindex a page table, wherein and the page table comprises a plurality ofpage table entries for storing a mapping between each of the virtualaddresses and a physical address.
 12. The memory access method in claim11, further comprising: using a translation look aside buffer (TLB) totemporarily store the page table entries which are most likely to beused by the AFU during accessing the memory.
 13. The memory accessmethod in claim 12, wherein: when the AFU fails to access the memorythrough the TLB, loading the corresponding page table entry from asystem memory of the processing system based on the page directory baseaddress.
 14. The memory access method in claim 9, further comprising:generating a plurality of memory access requests based on the task,wherein the data corresponding to the memory access requests is storedin the virtual addresses.
 15. The memory access method in claim 14,further comprising: arranging a scheduler; and scheduling the memoryaccess requests corresponding to the tasks through the scheduler; andsequentially transmitting the results of the memory access requests tothe AFU.
 16. The memory access method in claim 15, further comprising:arranging a pipeline resource; and receiving the memory access requeststransmitted by the scheduler so that the AFU executes the memory accessrequests for access the memory through the pipeline resource.